1 / 16

Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education

Space Charge Electric-Field Calculations for Coherent Tune Shift Estimations using the Electron-cloud Modelling Algorithm ECLOUD. Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education Electron Cloud Simulations Meeting Wilson Lab 14 January 2009.

dustin-wise
Download Presentation

Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Space Charge Electric-Field Calculations for Coherent Tune Shift Estimationsusing the Electron-cloud Modelling Algorithm ECLOUD Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education Electron Cloud Simulations Meeting Wilson Lab 14 January 2009

  2. Overview of Modelling Parameters and Data Sets CesrTA Electron Cloud Simulation wiki page: Simulation Guidance Parameters TS0407 CESR measurements in CESR-c configuration in April, 2007 1.89 GeV - Ten 0.75 mA bunches, followed by ten empty bunches, 14 ns spacing Beam RMS size 0.16 x 0.016 x 12.6 mm. ECLOUD bunch time +- 3.4 sigma: 0.29 ns Elliptical beam pipe 4.5 x 2.5 cm QE 10%, 0.23 s.r. photons per beam particle (mistake: should have been 0.53 for dipole) 25k macroparticles generated per filled bunch SEY parameters: SEY=1.8, Epk = 310 eV 150 steps per bunch length, 300 steps between bunches 11 field calculations during each of 20 bunches Transverse field grid 7x7 spanning +- 3 sigma Field calculation includes beampipe image charges, no contribution from beam Four data sets: e+ & e-(+- 5mm/grid sources), e+(+-0.5mm/grid sources),e+(+-5mm/cloud sources ) Ten runs per data set: zero beam offset, +- X and Y beam offsets, each for both drift and 715 G dipole volumes ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  3. e+, Drift volume, Beam Y + 5 mm Beam offset observed in cloud particle energies ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  4. e+, Vertical Field, Drift, Beam Y +- 5 mm No pinch effect present ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  5. e+, Vertical Field, Drift, Beam Y +- 5 mm Marco found a gradient about 25% larger for this case ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  6. e+, Vertical Field, Drift, Beam Y +- 5 mm Grid Field Sources (21x21) Macroparticle Field Sources ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  7. e+, Horizontal Field, Drift, Beam X +- 5 mm Some pinch effect present ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  8. e+, Horizontal Field, Drift, Beam X +- 5 mm Gradient factor 3 smaller than vertical ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  9. e+, Vertical Field, Drift, Beam Y +- 0.5 mm Some “pinch effect” present ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  10. e+, Vertical Field, Drift, Beam Y +- 0.5 mm Gradient factor 6 larger than for offset +- 5mm (?) ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  11. e+, Horizontal Field, Drift, Beam X +- 0.5 mm Some “pinch effect” present ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  12. e+, Horizontal Field, Drift, Beam X +- 0.5 mm Gradient again factor 6 larger than for offset +- 5mm (?) ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  13. e-, Vertical Field, Drift, Beam Y +- 5 mm No pinch effect present ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  14. e-, Vertical Field, Drift, Beam Y +- 5 mm Marco found a gradient about 25% larger for this case ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  15. e-, Horizontal Field, Drift, Beam X +- 5 mm Some pinch effect present ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

  16. e-, Horizontal Field, Drift, Beam X +- 5 mm ECLOUD Electric Field Calculations/ J.A.Crittenden 14 January 2009

More Related